|....CeeFish, what were you symptoms when you're went out?....|
Mine starting working intermittently, then ultimately gave up and would not engage.
One weird thing was happening just before it died...I’d be driving along and the 4x4 dash indicator lights would start blinking like I had shifted into 4x4 at too high of a speed. I’d have to pull over and restart the truck to get the lights to go off.
When I opened up the faulty actuator it was full of crud and some water. Apparently the vent nipple had broken off (I’m betting when the re-gear was done ) and allowed water to contaminate the unit.
New unit went in easily and everything work as designed.